Air conditioning apparatus

ABSTRACT

In an air conditioning apparatus of a type comprising a housing having air intake and discharge openings, a blower disposed in said housing, and a heat exchanger disposed in air flow passage of said blower, a centrifural flow type blower is employed as said blower and there is provided around the blower a spiral casing comprising a plurality of spiral segments which provide a plurality of air discharge ports.

United States Patent [191- Hosoda et al.

[ Apr. 23, 1974 AIR CONDITIONING APPARATUS [75] Inventors: Taisei Hosoda; Kyoichi Ogata;

Hideo Uzuhashi; l-liroyuki Ogawa; Akio Sakazume, all of Ohiramachi; Yozi Sekine, lwafunemachi; Kunio Fujie, Tokyo, all of Japan [73] Assignee: Hitachi, Ltd., Tokyo, Japan [22] Filed: Oct. 4, 1972 [21] Appl. No.: 294,803

[30] Foreign Application Priority Data Jewell 62/280 2,330,938 10/1943 Williams 415/219 C 2,341,871 2/1944 Karrer 415/204 2,357,362 9/1944 Smith.... 62/280 2,452,185 10/1948 Elleman 415/219 C 2,495,002 1/1950 Hart 62/280 2,730,873 1/1956 Harden 62/280 3,211,360 IQ/1 965 Lyman 415/219 C 3,394,755 7/1968 Morrison 165/103 3,472,146 10/1969 lnazurkiewicz 98/206 3,680,328 8/1972 McCarty 62/262 Primary Examiner-Williani J. Wye

. Attorney, Agent, or FirmCraig and Antonelli [5 7] ABSTRACT 2 Claims, 13 Drawing Figures PATENTEI] APR 2 3 I974 SHEET 1 OF 6 lllll FIG.

FIG. 3

1 AIR CONDITIONING APPARATUS The present invention relates to an improvement in an air conditioning apparatus.

An object of the present invention is to provide an air conditioning apparatus which is compact and has a lower noise level.

The air conditioning apparatus in accordance with the present invention is of such a type that comprises a housing having an air passage opening, a heat exchanger disposed in the housing and a blower for directing air to the heat exchanger. This type of heat exchanger is advantageous in that, since the heat exchanger and the blower are enclosed in the housing, it

can be easily handled and-placed, and operated with any-danger. Further, the apparatus can be designed with a preferable appearance and is free from dust deposition. Moreover, the apparatus can be readily cleaned and also easily packaged. Thus, the apparatus of this type has widely been used in homes, however, a serious problem encountered in this type of air conditioning apparatus is a relatively high level noise. This type of air conditioning apparatus generally uses an axial flow type as turbo blowenThe blowerof thistype operates with a high efficiency and produces less noise when flow resistance in air flow passage is very small, but the efficiency is remarkably reduced and a high level noise is produced when the air flow resistance is high. In the air conditioning apparatus of the aforementioned type, since the flow resistance at the air flow I passage opening in the housing is generally high, the

axial flow blower used therein operates with a low efficiency and produces a high level noise.

To eliminate the aforementioned problems, it may be conceived to use a centrifugal flow type blower in lieu of the axial flow type blower, because it has been found that a centrifugal flow type blower has a higher operating efficiency and produces less noise under a relatively high flow resistance as compared with an axial flow type blower. The use of a centrifugal flow type blower in an air conditioning apparatus may be effective to reduce noise level, however, in order to provide a sufficient. amount of flow byusing this type of blower, it is required to. provide aspiral casing of a substantial di mension for this blower to direct airflow from the blower to the air flow passage opening of the housing. If the dimension of the spiral casing is reduced to such a value that is consideredv to be equivalent to the casing for an axial flow type blower, there may be no merits obtained by the use of a centrifugal flow type blower in respect of the operating efficiency and the level of noise. Thus, in order to keep the advantageous feature of a centrifugal blower alive, it is necessary to use a spiral casing of a Substantial size which decreases an available space in the housing and makes it difficult to obtain a compact apparatus. Further, a centrifugal blower cannot be incorporated in a standardized air conditioning apparatus for home use.

The present invention has an important feature in that the spiral casing is divided into a plurality of segments so as to provide a plurality of discharge ports. In a centrifugal type blower, it is essential in reducing noise level to decrease the flow speed in the passage provided by the spiral casing. In a spiral casing having a single discharge port, the cross-sectional area of the passage in the spiral casing is gradually increasedalong the three quarter circumferential extent of the blower,

so that it is necessary to increase the dimension of the casing. In the arrangement of the present invention in which the casing is divided into a plurality of segments, if the casing is divided into two segments, a discharge port can be provided for each one-half circumferential extent of the blower with the rate of increase of the flow passage cross-sectional area which is the same as that in a single port spiral casing. Thus, the dimension of the spiral casing should not ncessarily be increased. Thus, it is not necessary, according to the present invention, to provide a spiral casing of a substantial size in combination with a centrifugal type blower in order to provide the same amount of air flow as in an arrangement in which an axial flow type bloweris used. Further, it is possible to provide an air conditioning apparatus which is compact but produces less noise.

According to the present invention, there is provided an air conditioning apparatus comprising a housing having an air intake opening and a plurality of air discharge openings, a centrifugal flow type blower disposed in the housing, and a spiral casing disposed about said centrifugal type blower and comprising a plurality of spiral segments to provide a plurality of discharge ports, and a heat exchanger disposed in an air flow passage of said centrifugal blower.

The above and other objects and features of the present invention will become apparent from the following descriptions of preferred embodiments which is illustrated in the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view of an air conditioning apparatus in accordance with the present invention;

FIG. 2 is a sectional view taken along the line II-II in FIG. 1;

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a fragmentary enlarged view of the segment shown in FIG. 3;

FIG. 5 is a longitudinal sectional view 'of another embodiment of the present invention;

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5;

FIG. 7 is a sectional view taken along the line VII- -VII in FIG. 6;

FIG. 8 is a longitudinal sectional view of a further embodiment of the present invention;

FIG. 9 is a sectional view taken along the line IX-IX in FIG. 8;

FIG. 10 is a sectional view taken along the line X-X in FIG. 9;

FIG. 11 is a longitudinal sectional view of a further embodiment of the present invention;

FIG. 12 is a sectional view taken along the line XII- -XII in FIG. 11; and

FIG. 13 is a sectional view taken along the line XIII- -XIII in FIG. 12.

Referring to the drawings, particularly to FIGS. 1 through 3 which show a first embodiment of the present invention, the reference numeral (1) designates a housing of an air conditioning apparatus having an air intake opening (la) at the front surface thereof and air discharge openings (lb) and (10) at the opposite side surfaces thereof. The numeral (2) designates a centrifugal flow type blower such as a multi-blade type centrifugal blower which takes air thereinto at the front surface thereof and discharges from the sides thereof. Around the centrifugal blower (2), there is disposed a circumferentially extending spiral casing (3) which comprises a mouth ring (3a) disposed at the front side, a back plate (3b) and a pair of spiral segments (3c) and (3d) which are disposed at the opposite sides of the blower. The mouth ring (3a) has an intake port (3e) for the centrifugal blower (2), and the spiral segments (30) and (3d) are so arranged to provide air outlet ports (3]) and (3g) which communicate with the air discharge openings (1b) and (1c). The spiral segments (30) and (3d) are positioned symmetrically with respect to the axis of the blower (2). The reference numeral (4) designates a blower motor having an output shaft connected to the centrifugal blower (2) and disposed in a shielded chamber (5) defined by the housing (1) and the back plate (3b) of the spiral casing (3). The numeral (6) designates a heat exchanger which provides a portion of cooling cycle together with a compressor (7) and serves as an evaporator when the apparatus is operated for cooling purpose, and as a condenser when the apparatus is operated for heating purpose. When the apparatus is operated for cooling purpose, compressed refrigerant is discharged outside the apparatus from the compressor (7) through a discharge line, not shown, and is cooled into liquified refrigerant in a suitable manner by cold water supplied from a source, which liquified refrigerant is fed to the evaporator (6) through a fed line, not shown. Since means for cooling compressed refrigerant by utilizing cold water and the conduits including the discharge and fed lines do not constitute a part of this invention, they are not shown nor disclosed herein in detail. In constrast, when the apparatus is operated for heating purpose, liquified refrigerant is discharged outside the apparatus from the condenser (6) through a discharge line, not shown, and is heated into volatized refrigerant in a suitable manner by hot water supplied from a source, which volatized refrigerant is fed to the compressor (7) through a fed line, not shown. The compressor (7) is housed in the shielded chamber (5). The shielded chamber (5) is connected to the inlet passage of the blower (2) by means of a conduit (8) and vented to the atmosphere through a vent hole (9).

In operation of the air conditioning apparatus constructed as described above, air is taken into the apparatus through the air intake opening (la) by means of the centrifugal blower (2), cooled or heated as the case may be by the heat exchanger (6) and introduced into the blower (2). Then, the air is discharged from the blower (2) and directed through the spiral segments (30) and (3d) to the discharge ports (3]) and (3g) to be discharged therefrom. Finally, the air is passed through the discharge openings (1b) and (1c) in the housing (1) to the room where the air conditioning apparatus is positioned. in the illustrated arrangement, since the spiral casing comprises two spiral segments (3c) and (3d), it is possible to decrease the increase in the flow resistance due to the provision of the spiral casing (3) to one-fourth as compared with an arrangement in which a single outlet spiral casing is used, because the illustrated arrangement is effective to reduce the air flow speed to one-half of that in a known arrangement. Thus, it is possible to reduce the noise level without increasing the dimension of the housing (1). Further, according to the arrangement of the present invention in which the spiral casing (3) has a pair of discharge ports (3]) and (33) at the opposite sides thereof for corresponding with the discharge openings (lb) and (1c) in the housing (1 it is possible to obtain a smooth air flow even with a small housing.

Further, in the above air conditioning apparatus, since the spiral segments (3c) and (3d) are disposed symmetrically with respect to the axis of the blower (2), it is possible to further decrease the noise level as compared with an asymmetrical arrangement. The illustrated arrangement is also desirable in that the load on the rotating blower shaft is well balanced and vibration of the blower can be remarkably decreased. Since the heat exchanger (6) is disposed in the intake passage of the centrifugal blower (2), turbulence of air flow can be decreased as compared with an arrangement in which the heat exchanger is disposed in the discharge passage of the blower and thus the noise level of the apparatus can be further reduced. Since the compressor (7 is disposed in the shielded chamber (5), the noise produced by the compressor 7) is not transmitted outside the apparatus. This feature is very important because, in an apparatus in which the noise level of the blower is remarkably reduced, the noise from the compressor has a substantial share in the total noise level. The air conduit (8) and the vent hole (9) serve to provide a sufficient cooling air flow for the compressor (7). The shielded chamber (5) for the compressor (7 is formed by the back plate (3b) of the blower casing (3) without adding any member. As an alternative arrangement, the conduit (8) may be omitted and the cooling air may be introduced into the shielded chamber (5) through a passage formed in the shaft of the blower motor (4).

A preferable shape of the spiral casing (3) will now be described taking reference to FIG. 4. The reference character (3h) designates the leading portion of the spiral segment (3d), and (3i) the leading portion of the segment (3c), both being bent radially outwardly of the centrifugal blower (2) in order to provide smooth air entrances. The trailing end portion of each spiral segment forms the air discharge port (3g) or (3f) with the leading portion (3h) or (3i) of the other segment. The character D designates the external diameter of the blower (2), Ad and Ac the distances from the blower (2) to the leading portions (3h) and (3i), Ed and Be the distances from the outer periphery of the blower (2) to the inner surfaces of the spiral segments (3d) and (3c), respectively at the trailing portions thereof. The characters 0d and 6c designate angular distances from the leading ends of the portions (3h) and (3i) to the horizontal center line of the blower (2). In this instance, when the ratio Ad to Ac is determined 1 4 or below and the values of Ad/D and Ac/D are between 0.02 and 0.2, preferable results can be obtained in respect to the air flow and the operating efficiency of the blower and the apparatus can be operated with less noise. When the ratio Ad/D or Ac/D is below 0.02, a piping noise is produced and, when the ratio is over 0.2, a portion of blower output air flows from either the discharge ports (3f) or (3g) to the adjacent intake port Ad or Ac producing a noise and resulting in a reduced air pressure. With respect to the dimensions Bd and Be, when the ratio of Be to Ed is below 1 to 4 and the ratio Bd/D and Bc/D are between 0.1 and 0.4, preferable results can be obtained in respect of the air flow and the blower efficiency, with less operating noise. When the ratio Bd/D or Bc/D is less than 0.1, the air flow speed is so increased that noise is remarkably increased and the amount of air flow is decreased due to an increase in flow resistance. Thus, the operating efficiency is decreased. When the ratio is over 0.4, the spiral segment (3d) or (30) do not serve its purpose and the discharged air is allowed to flow back around the centrifugal blower (2) resulting in an increased noise and a reduced discharge pressure. The ratio of Rd to Ad or Bc to Ac should preferably be 2 to 10. If the ratio is out of this range, the spiral segment does not serve its purpose anymore and the performance of the blower is remarkably decreased and noise level is increased to an unacceptable value.

The ratio of angle ad to ac or ac to ad should preferably be 1 to 3 and a preferable range of each of the angle ad and ac is between 45 and 135. If the angle is less than 45 or over l35, a decrease in performance will be encountered. The angle d or (is should be between 45 and +30 as measured from the horizontal center line in order to provide a preferable result in respect of the amount of air flow, the blower operating efficiency and the noise level. When the angle is out of this range, a piping noise is produced or the amount of airflow and the discharge air pressure are decreased.

Another embodiment of the present invention will now be described taking reference to FIGS. 5 to 7. The air conditioning apparatus includes a housing (1 1) having an air intake port (110) at the rear surface, air discharge ports (11b) and (110) at the opposite sides thereof, and an air vent hole (11d) at the front surface thereof. Within the housing (11), there is disposed a centrifugal flow type blower (12) which having larger blades and smaller blades at opposite sides of a partition disc as shown in FIGS. 5 and 6, takes air thereinto from the front and reat surfaces and discharges it from the periphery thereof. Around the blower (12), there is disposed a spiral casing (13) which comprisesa pair of mouth rings (13a) and (13b) respectively disposed at the rear and front surfaces of the blower, and a pair of spiral segments (13c) and (13d) disposed along the periphery of the blower (12). The mouth ring (13a) is provided with an air intake port (13c) for the blower (12) and the mouth ring (1317) is provided with an airintake port (13]) and also defines a shielded chamber (14) together with the housing (11). In this arrangement, air is'allowed to flow from the air vent hole (11d) through the shielded chamber (14) into the air intake port (13]). The spiral segments (13c) and (13d) are provided with air discharge ports (13g) .and(l3h), respectively, which are positioned in confronting relationship with the air discharge openings (11b) and (11c) of the housing (11). The air discharge ports (13g) and (13h) are positioned in symmetrical relation with respect to the axis of the blower (12). A blower motor (15) is disposed in the shielded chamber (14) and operatively connected to the centrifugal blower (12). A compressor (16) is also disposed in the shielded chamber (14) with a side-by-side relation with the blower motor (15). The reference numeral (17) designates a heat exchanger which constitutes a portion of a cooling cycle together with the compressor (16). When the apparatus is used for cooling purpose, the heat exchanger serves as an evaporator, while when the apparatus is used for heating purpose, it serves as a condenser.

The apparatus as constructed above has advantageous features as in the embodiment shown in FIGS. 1 through 3. In addition, the apparatus has the following advantages. Namely, the use of a dual-intake type centrifugal blower (12) is effective to compensate the decrease in air flow passage for the blower which is caused by the provision of the shielded chamber (14) for preventing the noise of the compressor (16) from being transmitted outside the apparatus. Further, since the air in the shielded chamber (14) is directly introduced into the blower, the compressor cooling air passage construction can be made very simple. Still further, the provision of a dual-intake type blower is effective to have axially balanced loads on the blower, resulting in a reduced vibration.

A further embodiment of the present invention will now be described .taking reference to FIGS. 7 through 9. The drawings show a window type air conditioning apparatus comprising a housing (21) which is adapted to be mounted through a wall (22). The housing (21) has an open front end to which a decorating cover (23) is attached. The cover (23) is provided with an air intake port (23a) and an air discharge port (23b). The portion of the housing 21) that is disposed outside the room has a rear surface which is provided with an air intake opening (21a) and side surfaces which are provided with air discharge openings (21b) and (21c). The reference numerals (24) and (25) designate partition plates for separating the interior space of the housing (21) into an inboard space (26), an outboard space (27) and a shielded chamber (28), the plate (24) separating the space (26) and the shielded chamber (28) and the plate (25) separating the shielded chamber (28) and the space (27). In the space (26), there is disposed a centrifugal flow type blower (29) which takes air thereinto from the front .side and discharges the air from the periphery thereof. Around the blower (29), there is disposed a spiral casing comprising a mouth ring (30a) disposed at the front surface of the blower, and a spiral segment (30b) at the periphery of the blower. Further, the partition plate (24) also constitute a portion of the spiral casing (30). The mouth ring (30a) is formed with an air-intake port (30c) for the blower (29) and the spiral segment (30b) is formed with an air discharge port(30d) which is positioned in confronting relation with the air discharge opening (23b) in the housing (21). In the inlet side of the blower (29), there is disposed an evaporator (31) which serves to cool the air in the room. A second centrifugal type-blower (32) is provided in. the space (27) of the housing (21) which serves to take air thereinto from the rear side and discharge from the periphery thereof. A second spiral casing (33) is disposed around the second blower (32) and comprises a mouth ring (33a) at the rear side thereof and a pair of spiral segments (33b) and (33c) at the peripheral portion thereof. The partition plate (25) also takes-a part of the spiral casing (33). The mouth ring (33a) is formed with an air intake port (33d) for the centrifugal blower (32) and the spiral segments (33b) and (33c) are formed with air discharge ports (33c) and (33)), respectively, which are in communication with the air discharge openings (21b) and (21c) in the housing (21 The spiral segements (33b) and (330) are positioned in symmetrical relation with respect to the axis of the blower (32). A condenser (34) is disposed at the inlet side of the blower (32) for cooling the air from the compressor. A blower motor (35) is-provided in the shielded chamber (28) and operatively connected to the blowers (29) and (32). The reference numeral (36) designates a compressor disposed in the shielded chamber (28) and constituting a cooling cycle together with the evaporator (31) and the condenser (34). The numeral (37) designates a dew tray disposed directly beneath the evaporator (31) for receiving water dipping from the evaporator (31). A conduit (38) is connected to the dew tray (37) for directing the water in the tray (37) to the bottom of the space (27). [n the space (27), there is provided a slinger ring (39) which is driven by the centrifugal blower (32) for spattering the water collected in the space (27) toward the condenser.

The air conditioning apparatus as described above can provide advantages as in theembodiment shown in FIGS. 1 through 3. In addition, the apparatus provides further advantages in that the noise from the second centrifugal blower (32) is shielded by two partition plates (24) and (25), so that the noise level can be remarkably reduced. Since the compressor (36) and the blower motor (35) are disposed at the longitudinal outer portion of the housing, and the partition plates (24) and (25), the blowers (29) and (32), and the heat exchangers (3]) and (34) are arranged in symmetrical relationship with respect to the compressor (36) and the blower motor (35), the window type air conditioning apparatus can be stably positioned on the wall. Further, the operating efficiency can be further increased by the arrangement in which the condensed water is spattered to the condenser (34). It is of course possible to decrease the noise level of the room blower (29) by using a centrifugal flow type blower as the room blower (29) and providing a spiral casing comprising a plurality of spiral segments for forming a plurality of discharge ports.

FIGS. 11 through 13 show a further embodiment of the present invention which is obtained by combining the arrangement of FIG. 5 through 7 with that of FIGS. 8 through 10. 7

Although the invention has thus been described with reference to preferred embodiments, the present invention is in no way limited to the details of the illustrated structures but many changes and modifications can be made without departing from the scope of the appended claims.

We claim:

1. An air conditioning apparatus comprising a housing having an air intake opening at the rear surface thereof and a plurality of air discharge openings at the opposite side surfaces thereof; a dual-inlet type centrifugal blower disposed in said housing, said blower including a partition disc and a plurality of larger and smaller blades, said larger blades being provided at a rear side of said partition disc and said smaller blades being provided at the front side of said disc; a spiral casing comprising a pair of spiral segments disposed along the periphery of said blower, said spiral segments providing two air discharge ports which are positioned in confronting relationship with said air discharge openings at the opposite side surfaces of said housing, a rear plate disposed at the rear side of said blower for separating an air intake flow passage from air discharge passages provided with an air intake port for said blower, and a front plate disposed at the front side of said blower for separating the interior space of said housing into two spaces, said front plate being provided with an intake port for said blower; a heat exchanger disposed in an air intake flow passage defined between said rear plate of said spiral casing and said air intake opening of said housing; a shielded chamber defined by said front plate of said spiral casing, said partition disc of said blower, and said housing, said housing being provided with an air vent hole at the front surface thereof; and a compressor accommodated in said shielded chamber.

2. An air conditioning apparatus comprising a housing separating the interior space thereof into an inboard space and an outboard space by means of first and second partition plates, said housing having an air intake port and an air discharge port at the front surface thereof, an air intake opening at the rear surface thereof, and air discharge openings at the opposite side surfaces thereof; a first single-inlet type centrifugal blower disposed within said inboard space of said housing taking air thereinto from said front side thereof; an evaporator disposed at said inlet side of said first blower; a second dual-inlet type centrifigual blower disposed within said outboard space of said housing, said second blower including a partition disc, and a plurality of large and small blades, said large blades being provided at a rear side of said partition disc and said small blades being provided at the front side of said disc; a spiral casing comprising a pair of spiral segments disposed along the periphery of said second blower, said spiral segments providing two air discharge ports which are positioned in confronting relationship with said air discharge openings at said opposite side surfaces of said housing, a rear plate disposed at the rear side of said second blower for separating an air intake flow passage from air discharge flow passages, said rear plate being formed with an air intake port for said second blower, and a side plate serving as said second partition plate disposed at the front side of said second blower, said side plate being formed with an air intake port for said second blower; a condenser disposed in an air intake flow passage defined between said rear plate of said spiral casing and said air intake opening at said rear surface of said housing; a shielded chamber defined by said second partition plate of said spiral casing, said partition disc of said second blower, said first partition plate, and said housing, said housing being provided with air vent holes; and a compressor and blower motor accommodated in said shielded chamber in side by side relationship, said compressor constituting a part of a cooling cycle together with said condenser within the outboard space and said evaporator within said inboard space, said blower motor being operatively connected to said first and second blowers.

I i k 

1. An air conditioning apparatus comprising a housing having an air intake opening at the rear surface thereof and a plurality of air discharge openings at the opposite side surfaces thereof; a dual-inlet type centrifugal blower disposed in said housing, said blower including a partition disc and a plurality of larger and smaller blades, said larger blades being provided at a rear side of said partition disc and said smaller blades being provided at the front side of said disc; a spiral casing comprising a pair of spiral segments disposed along the periphery of said blower, said spiral segments providing two air discharge ports which are positioned in confronting relationship with said air discharge openings at the opposite side surfaces of said housing, a rear plate disposed at the rear side of said blower for separating an air intake flow passage from air discharge passages provided with an air intake port for said blower, and a front plate disposed at the front side of said blower for separating the interior space of said housing into two spaces, said front plate being provided with an intake port for said blower; a heat exchanger disposed in an air intake flow passage defined between said rear plate of said spiral casing and said air intake opening of said housing; a shielded chamber defined by said front plate of said spiral casing, said partition disc of said blower, and said housing, said housing being provided with an air vent hole at the front surface thereof; and a compressor accommodated in said shielded chamber.
 2. An air conditioning apparatus comprising a housing separating the interior space thereof into an inboard space and an outboard space by means of first and second partition plates, said housing having an air intake port and an air discharge port at the front surface thereof, an air intake opening at the rear surface thereof, and air discharge openings at the opposite side surfaces thereof; a first single-inlet type centrifugal blower disposed within said inboard space of said housing taking air thereinto from said front side thereof; an evaporator disposed at said inlet side of said first blower; a second dual-inlet type centrifigual blower disposed within said outboard space of said housing, said second blower including a partition disc, and a plurality of large and small blades, said large blades being provided at a rear side of said partition disc and said small blades being provided at the front side of said disc; a spiral casing comprising a pair of spiral segments disposed aloNg the periphery of said second blower, said spiral segments providing two air discharge ports which are positioned in confronting relationship with said air discharge openings at said opposite side surfaces of said housing, a rear plate disposed at the rear side of said second blower for separating an air intake flow passage from air discharge flow passages, said rear plate being formed with an air intake port for said second blower, and a side plate serving as said second partition plate disposed at the front side of said second blower, said side plate being formed with an air intake port for said second blower; a condenser disposed in an air intake flow passage defined between said rear plate of said spiral casing and said air intake opening at said rear surface of said housing; a shielded chamber defined by said second partition plate of said spiral casing, said partition disc of said second blower, said first partition plate, and said housing, said housing being provided with air vent holes; and a compressor and blower motor accommodated in said shielded chamber in side by side relationship, said compressor constituting a part of a cooling cycle together with said condenser within the outboard space and said evaporator within said inboard space, said blower motor being operatively connected to said first and second blowers. 